ARRL

Forum Home - Rules - Help - Login - Forgot Password
Members can access, post and reply to the forums below. Before you do, please first read the RULES.

Removing Corrosion from copper wire

Aug 23rd 2011, 13:20

N4PO

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
I have a coil of "new" stranded copper wire that I bought several years ago and didn't use at the time.

I need to repair a dipole antenna that came down in a tornado (a tree fell on it) and noticed that there is some corrosion which prevents the wire from wicking the solder for a good clean tinning/solder job.

A fellow ham in the area suggested using either distilled vinegar or ammonia to remove the corrosion. I did a test using both and used a solution of baking soda to neutralize the process after soaking the test pieces overnight. I found that neither worked - the copper looked clean enough, but it still did not wick the solder and the solder on the surface had the appearance of a typical cold solder joint..

Someone who works with silver solder on jewelry suggested using hydrochloric acid, but I don't trust using a corrosive acid again.

Asking ASK.COM, I saw a suggestion to use one of the copper cleaners for copper clad cooking pots. I haven't tried it yet and wondered if anyone would care to share experience with this or another method. I wonder if the wire would have to be unbraided to be able to clean the inside ot the strand.

Any and all suggestions will be appreciated!

Arlen Morgan - n4po
(n4po@juno.com)
Aug 23rd 2011, 15:58

W1VT

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0

You might consider the need for a bigger heat source--it may be possible that the wire is clean enough but you aren't getting the copper hot enough for it to melt the solder.

Zack Lau W1VT
ARRL Senior Lab Engineer

Aug 23rd 2011, 16:28

N4PO

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Zack,

I appreciate the prompt reply and appreciate the suggestion. I had thought of this possibility, but have never had any problems before even when soldering RG8 braid to a PL259 coax connector.

I am using a weller 140 watt gun with a brand new tip as well. I am, however using 60/40 resin core solder that is fairly thin (I had run out of the thicker stuff for heavier duty), so my next step - besides trying to find a better way of removing the corrosion - was going to be a trip to the electronics store to replenish my roll of thicker solder.

Meantime, I'd appreciate your thoughts about the thickness, although I have always been able to get good results simply by using a longer piece of the thinner solder. You might also ask around, if you don't mind, about the compatibility of the copper pot cleaners with electronic applications.

Agn, Tnx es 73,

N4PO, Arlen
Aug 23rd 2011, 17:02

W1VT

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
It sounds like you have enough heat, unless you are trying to solder out in the open with some wind--in which case you very well need more heat. No, thinner solder should not be an issue.

Joe, the chief operator at W1AW suggests that you can use liquid flux for pipes found at home improvement stores.

But, the most popular method is to clean it off with fine sandpaper--there is no acid residue that needs to be removed.

Zack Lau
ARRL Senior Lab Engineer
Aug 24th 2011, 17:33

KE8DO

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
You may now be using the newer lead free solder that has a higher melting point.
73 Don
Aug 24th 2011, 18:13

AC5JW

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Hello Arlen,

For solid and stranded copper wire, I have had some success with using steel wool, ranging from the fluffy and soft to the abrasive and coarse. Watch your fingers and hands with the more abrasive kinds.

But, I have never soldered the wire after cleaning it, so I don't know if it will be clean enough for soldering and your own requirements.

All I know is the wire becomes hot when you wrap the steel wool around it and either pull or push-pull the steel wool up and down the line, making it very shiny. You can probably clean the amount you need easier if you clean it before removing it from the spool, which will help to anchor the wire as you clean it.

Consider eye protection as you will want to blow off the excess from the cleaned wire and you may have a slight mess of steel wool to clean up.

73, Raleigh
AC5JW
Aug 28th 2011, 15:30

W1RFIAdmin

Joined: Jul 25th 2011, 14:25
Total Topics: 0
Total Posts: 0
It's possible that water (or ???) wicked up into the stranding of the wire. If you cut of 2 or 3 feet, you may find that the wire is in good condition past that point.

If not, there is something really odd about the wire. In that case, I would be inclined to just toss that wire and buy some new wire. If for some reason, the copper is corroded, it is likely that you will run into this again and again. Although the price of copper is high right now, as is the cost of wire, in the long run, you will be glad to have good wire to use for antennas and other projects.

73,
Ed, W1RFI
ARRL Lab
Technical forums moderator

Back to Top